using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
using System.Threading;
using System.Runtime.CompilerServices;
using System.Diagnostics;
using nint=System.Int32;
static class Program {
	const long inf = long.MaxValue>>1;
	const int mod = 998244353;
	static Sc sc = new Sc();
	static void Main() {
		Pt pt = new Pt(Solve);
		pt.Sm();
	}
	static void Solve(Pt pt) {
		var n = sc.I;
		var a = sc.Ia2;
		int g = 0;
		int m = 25;
		var avl = new Avl[m];
		var avl2 = new Avl[75001];
		for(int i = 0;i<avl2.Length;i++) {
			avl2[i]=new Avl();
		}
		for(int i = 0;i<m;i++) {
			avl[i]=new Avl();
		}
		for(int i = 1;i<=n;i++) {
			g^=a[i];
			for(int j = 0;j<m;j++) {
				if(((1<<j)&a[i])!=0) {
					avl[j].Ud(a[i]);
					avl2[a[i]].Ud(i);
				}
			}
		}
		Console.WriteLine(g==0?0:1);
		if(g!=0) { Fu(); }
		while(true) {
			var (i, k)=sc.Tp2<int>();
			var z = sc.I;
			if(z==-1) { break; }
			Fo(i,k);
			z=Fu();
			if(z==-1) { break; }
		}
		int Fu() {
			var l = (int)Log(g,2);
			var e = avl[l].Ra(1);
			var d = e.n^g;
			d=e.n-d;
			var p = avl2[e.n].Ra(1).n;
			Console.WriteLine("{0} {1}",p,d);
			Fo(p,d);
			return sc.I;
		}
		void Fo(int i,int k) {
			for(int j = 0;j<m;j++) {
				if((a[i]&(1<<j))!=0) { avl[j].Dl(a[i]); }
			}
			avl2[a[i]].Dl(i);
			g^=a[i];
			a[i]-=k;
			g^=a[i];
			avl2[a[i]].Ud(i);
			for(int j = 0;j<m;j++) {
				if((a[i]&(1<<j))!=0) { avl[j].Ud(a[i]); }
			}
		}
	}
}
public class Avl {
	public class Nd {
		public int h = 1, c = 1;
		public readonly nint n;
		public Nd l, r;
		public Nd(nint n,Nd du) { this.n=n; l=du; r=du; }
	}
	public Nd root, du;
	public int cnt = 0;
	public Avl() {
		du=new Nd(nint.MinValue,du); du.h=0; du.c=0;
		root=du;
	}
	public Avl(Avl z) {
		du=new Nd(nint.MinValue,du); du.h=0; du.c=0;
		root=Fu(z.root);
		cnt=z.cnt;
		Nd Fu(Nd nd) {
			if(nd.h==0) { return du; }
			Nd mn = new Nd(nd.n,du);
			mn.h=nd.h;
			mn.c=nd.c;
			mn.l=Fu(nd.l);
			mn.r=Fu(nd.r);
			return mn;
		}
	}
	public void Ud(nint n) {
		Nd mn = new Nd(n,du);
		if(root==du) { root=mn; }
		else {
			Fu(root,mn);
			if(Abs(root.l.h-root.r.h)>1) { root=Rotate(root); }
		}
		cnt++;
	}
	private void Fu(Nd t,Nd mn) {
		t.c++;
		if(t.n>mn.n) {
			if(t.l!=du) {
				Fu(t.l,mn);
				if(Abs(t.l.l.h-t.l.r.h)>1) { t.l=Rotate(t.l); }
			}
			else { t.l=mn; }
		}
		else {
			if(t.r!=du) {
				Fu(t.r,mn);
				if(Abs(t.r.l.h-t.r.r.h)>1) { t.r=Rotate(t.r); }
			}
			else { t.r=mn; }
		}
		t.h=Max(t.l.h,t.r.h)+1;
	}
	private Nd Rotate(Nd t) {
		Nd nd = du;
		if(t.l.h>t.r.h) {
			if(t.l.l.h>t.l.r.h) {
				nd=t.l; t.l=t.l.r; nd.r=t;
				t.h=Max(t.l.h,t.r.h)+1;
				t.c=t.l.c+t.r.c+1;
			}
			else {
				nd=t.l.r;
				t.l.r=nd.l; nd.l=t.l;
				t.l.h=Max(t.l.l.h,t.l.r.h)+1;
				t.l.c=t.l.l.c+t.l.r.c+1;
				t.l=nd.r; nd.r=t;
				t.h=Max(t.l.h,t.r.h)+1;
				t.c=t.l.c+t.r.c+1;
			}
		}
		else {
			if(t.r.l.h>t.r.r.h) {
				nd=t.r.l;
				t.r.l=nd.r; nd.r=t.r;
				t.r.h=Max(t.r.l.h,t.r.r.h)+1;
				t.r.c=t.r.l.c+t.r.r.c+1;
				t.r=nd.l; nd.l=t;
				t.h=Max(t.l.h,t.r.h)+1;
				t.c=t.l.c+t.r.c+1;
			}
			else {
				nd=t.r; t.r=t.r.l; nd.l=t;
				t.h=Max(t.l.h,t.r.h)+1;
				t.c=t.l.c+t.r.c+1;
			}
		}
		nd.h=Max(nd.l.h,nd.r.h)+1;
		nd.c=nd.l.c+nd.r.c+1;
		return nd;
	}
	public bool Dl(nint n) {
		if(cnt==0) { return false; }
		Nd t = root;
		if(t.n==n) {
			root=Fd2(root);
			if(cnt==0) { return true; }
			else if(Abs(root.l.h-root.r.h)>1) { root=Rotate(root); }
			else {
				root.h=Max(root.l.h,root.r.h)+1;
				root.c=root.l.c+root.r.c+1;
			}
			return true;
		}
		bool bo = Fd1(root,n);
		if(Abs(root.l.h-root.r.h)>1) { root=Rotate(root); }
		else {
			root.h=Max(root.l.h,root.r.h)+1;
			root.c=root.l.c+root.r.c+1;
		}
		return bo;
	}
	private bool Fd1(Nd t,nint n) {
		if(t.n>n) {
			if(t.l==du) { return false; }
			else if(t.l.n!=n) {
				bool bo = Fd1(t.l,n);
				if(Abs(t.l.l.h-t.l.r.h)>1) { t.l=Rotate(t.l); }
				else {
					t.l.h=Max(t.l.l.h,t.l.r.h)+1;
					t.l.c=t.l.l.c+t.l.r.c+1;
				}
				return bo;
			}
			else {
				t.l=Fd2(t.l);
				t.h=Max(t.l.h,t.r.h)+1;
				t.c=t.l.c+t.r.c+1;
				return true;
			}
		}
		else {
			if(t.r==du) { return false; }
			else if(t.r.n!=n) {
				bool bo = Fd1(t.r,n);
				if(Abs(t.r.l.h-t.r.r.h)>1) { t.r=Rotate(t.r); }
				else {
					t.r.h=Max(t.r.l.h,t.r.r.h)+1;
					t.r.c=t.r.l.c+t.r.r.c+1;
				}
				return bo;
			}
			else {
				t.r=Fd2(t.r);
				t.h=Max(t.l.h,t.r.h)+1;
				t.c=t.l.c+t.r.c+1;
				return true;
			}
		}
	}
	private Nd Fd2(Nd dn) {
		cnt--;
		if(dn.l==du) { return dn.r; }
		if(dn.r==du) { return dn.l; }
		Nd u = dn.l;
		if(u.r==du) {
			u.r=dn.r;
			u.h=Max(u.l.h,u.r.h)+1;
			u.c=u.l.c+u.r.c+1;
			return u;
		}
		u=Fd3(u,dn);
		if(Abs(dn.l.l.h-dn.l.r.h)>1) { u.l=Rotate(dn.l); }
		else {
			dn.l.h=Max(dn.l.l.h,dn.l.r.h)+1;
			dn.l.c=dn.l.l.c+dn.l.r.c+1;
		}
		u.h=Max(u.l.h,u.r.h)+1;
		u.c=u.l.c+u.r.c+1;
		return u;
	}
	private Nd Fd3(Nd u,Nd dn) {
		if(u.r.r!=du) {
			Nd v = Fd3(u.r,dn);
			if(Abs(u.r.l.h-u.r.r.h)>1) { u.r=Rotate(u.r); }
			else {
				u.r.h=Max(u.r.l.h,u.r.r.h)+1;
				u.r.c=u.r.l.c+u.r.r.c+1;
			}
			return v;
		}
		else {
			Nd v = u.r; u.r=u.r.l; v.l=dn.l; v.r=dn.r;
			return v;
		}
	}
	public bool Hs(nint n) {
		Nd t = root;
		if(cnt==0) { return false; }
		if(t.n==n) { return true; }
		bool bo = false;
		while(true) {
			if(t.n>n) {
				if(t.l==du) { break; }
				else if(t.l.n!=n) { t=t.l; }
				else { bo=true; break; }
			}
			else {
				if(t.r==du) { break; }
				else if(t.r.n!=n) { t=t.r; }
				else { bo=true; break; }
			}
		}
		return bo;
	}
	public Nd Ra(int n) { return cnt>=n&&cnt!=0 ? Fr(root,n) : null; }
	private Nd Fr(Nd t,int n) {
		if(t.l.c>n-1) { return Fr(t.l,n); }
		if(t.l.c<n-1) { return Fr(t.r,n-t.l.c-1); }
		return t;
	}
	public Nd Lb(nint n) { return cnt!=0 ? Flb(root,n) : null; }
	private Nd Flb(Nd t,nint n) {
		if(t.n<n) {
			if(t.r==du) { return null; }
			return Flb(t.r,n);
		}
		if(t.n>n) {
			if(t.l==du) { return t; }
			Nd u = Flb(t.l,n);
			return u==null ? t : u;
		}
		return t;
	}
	public Nd Ub(nint n) { return cnt!=0 ? Fub(root,n) : null; }
	private Nd Fub(Nd t,nint n) {
		if(t.n>n) {
			if(t.l==du) { return null; }
			return Fub(t.l,n);
		}
		if(t.n<n) {
			if(t.r==du) { return t; }
			Nd u = Fub(t.r,n);
			return u==null ? t : u;
		}
		return t;
	}
	public int Rg(nint a,nint b) { return cnt!=0 ? Frg(root,a,b,false,false) : 0; }
	private int Frg(Nd t,nint a,nint b,bool l,bool r) {
		if(t.h==0) { return 0; }
		if(l&&r) { return t.c; }
		if(t.n<a) { return Frg(t.r,a,b,t.n>=a,r); }
		if(t.n>b) { return Frg(t.l,a,b,l,t.n<=b); }
		return Frg(t.l,a,b,l,t.n<=b)+Frg(t.r,a,b,t.n>=a,r)+1;
	}
	public void En(Action<Nd> f) { if(cnt>0) { Fen(root,f); } }
	private void Fen(Nd t,Action<Nd> f) {
		if(t.l!=du) { Fen(t.l,f); }
		f(t);
		if(t.r!=du) { Fen(t.r,f); }
	}
	public void En(nint l,nint r,Action<Nd> f) { if(cnt>0) { Fen(root,l,r,false,false,f); } }
	private void Fen(Nd t,nint a,nint b,bool l,bool r,Action<Nd> f) {
		if(l&&r) {
			if(t.l!=du) { Fen(t.l,f); }
			f(t);
			if(t.r!=du) { Fen(t.r,f); }
		}
		else {
			if(t.n<a) { if(t.r!=du) { Fen(t.r,a,b,l,r,f); } }
			else if(t.n>b) { if(t.l!=du) { Fen(t.l,a,b,l,r,f); } }
			else {
				if(t.l!=du) { Fen(t.l,a,b,l,t.n<=b,f); }
				f(t);
				if(t.r!=du) { Fen(t.r,a,b,t.n>=a,r,f); }
			}
		}
	}
	public void Enl(nint l,Func<Nd,bool> f) { if(cnt>0) { Fenl(root,l,f); } }
	private bool Fenl(Nd t,nint a,Func<Nd,bool> f) {
		bool bo = true;
		if(t.n<a) {
			if(t.r!=du) { bo&=Fenl(t.r,a,f); }
		}
		else {
			if(t.l!=du) { bo&=Fenl(t.l,a,f); }
			if(bo) { bo&=f(t); }
			if(bo&&t.r!=du) { bo&=Fenl(t.r,a,f); }
		}
		return bo;
	}
	public void Enr(nint r,Func<Nd,bool> f) { if(cnt>0) { Fenr(root,r,f); } }
	private bool Fenr(Nd t,nint b,Func<Nd,bool> f) {
		bool bo = true;
		if(t.n>b) {
			if(t.l!=du) { bo&=Fenr(t.l,b,f); }
		}
		else {
			if(t.r!=du) { bo&=Fenr(t.r,b,f); }
			if(bo) { bo&=f(t); }
			if(bo&&t.l!=du) { bo&=Fenr(t.l,b,f); }
		}
		return bo;
	}
}
public class Pt {
	private StringBuilder sb = new StringBuilder();
	public Pt(Action<Pt> f) { f(this); }
	public void W(int s) { sb.Append(s); }
	public void W(long s) { sb.Append(s); }
	public void W(double s) { sb.Append(s); }
	public void W(decimal s) { sb.Append(s); }
	public void W(char s) { sb.Append(s); }
	public void W(string s) { sb.Append(s); }
	public void W(object s) { sb.Append(s); }
	public void W(params object[] s) { sb.Append(string.Join(" ",s)); }
	public void Wl(int s) { sb.Append(s).AppendLine(); }
	public void Wl(long s) { sb.Append(s).AppendLine(); }
	public void Wl(double s) { sb.Append(s).AppendLine(); }
	public void Wl(decimal s) { sb.Append(s).AppendLine(); }
	public void Wl(char s) { sb.Append(s).AppendLine(); }
	public void Wl(string s) { sb.AppendLine(s); }
	public void Wl(object s) { sb.Append(s).AppendLine(); }
	public void Wl(int[] s) { sb.AppendLine(string.Join(" ",s)); }
	public void Wl(long[] s) { sb.AppendLine(string.Join(" ",s)); }
	public void Wl(double[] s) { sb.AppendLine(string.Join(" ",s)); }
	public void Wl(string[] s) { sb.AppendLine(string.Join(" ",s)); }
	public void Wl(params object[] s) { sb.AppendLine(string.Join(" ",s)); }
	public void Wl() { sb.AppendLine(); }
	public void Sm() { Console.Write(sb); }
	public void Op(StreamWriter sw) {
		sw.Write(sb);
		sw.Close();
	}
	public static bool operator ==(Pt a,Pt b) { return a.sb.ToString()==b.sb.ToString(); }
	public static bool operator !=(Pt a,Pt b) { return a.sb.ToString()!=b.sb.ToString(); }
	public override bool Equals(object obj) { return false; }
	public override int GetHashCode() { return 0; }
}
public class Sc {
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	protected virtual string Rl() { return Console.ReadLine(); }
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	protected virtual string[] Sp(string st) { return st.Split(); }
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	private T Ct<T>(string s) { return (T)Convert.ChangeType(s,typeof(T)); }
	public virtual int I { get { return int.Parse(Rl()); } }
	public virtual long L { get { return long.Parse(Rl()); } }
	public virtual double D { get { return double.Parse(Rl()); } }
	public virtual string S { get { return Rl(); } }
	public int[] Ia { get { return Array.ConvertAll(Sp(Rl()),int.Parse); } }
	public long[] La { get { return Array.ConvertAll(Sp(Rl()),long.Parse); } }
	public double[] Da { get { return Array.ConvertAll(Sp(Rl()),double.Parse); } }
	public string[] Sa { get { return Sp(Rl()); } }
	public object[] Oa { get { return Sp(Rl()); } }
	public int[] Ia2 { get { return Array.ConvertAll(Sp("0 "+Rl()+" 0"),int.Parse); } }
	public int[] Ia3(string a,string b) { return Array.ConvertAll(Sp(a+Rl()+b),int.Parse); }
	public int[] Ia3(int a) { return Array.ConvertAll(Sp(Rl()+" "+a.ToString()),int.Parse); }
	public long[] La2 { get { return Array.ConvertAll(Sp("0 "+Rl()+" 0"),long.Parse); } }
	public long[] La3(string a,string b) { return Array.ConvertAll(Sp(a+Rl()+b),long.Parse); }
	public long[] La3(int a) { return Array.ConvertAll(Sp(Rl()+" "+a.ToString()),long.Parse); }
	public double[] Da2 { get { return Array.ConvertAll(Sp("0 "+Rl()+" 0"),double.Parse); } }
	public double[] Da3(string a,string b) { return Array.ConvertAll(Sp(a+Rl()+b),double.Parse); }
	public T[] Arr<T>(int n,Func<T> f) { var a = new T[n]; for(int i = 0;i<n;i++) { a[i]=f(); } return a; }
	public T[] Arr<T>(int n,Func<int,T> f) { var a = new T[n]; for(int i = 0;i<n;i++) { a[i]=f(i); } return a; }
	public T[] Arr<T>(int n,Func<string[],T> f) { var a = new T[n]; for(int i = 0;i<n;i++) { a[i]=f(Sp(Rl())); } return a; }
	public T[] Arr<T>(int n,Func<int,string[],T> f) { var a = new T[n]; for(int i = 0;i<n;i++) { a[i]=f(i,Sp(Rl())); } return a; }
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T, T) Tp2<T>() { var s = Sp(Rl()); return (Ct<T>(s[0]), Ct<T>(s[1])); }
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T, T, T) Tp3<T>() { var s = Sp(Rl()); return (Ct<T>(s[0]), Ct<T>(s[1]), Ct<T>(s[2])); }
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T, T, T, T) Tp4<T>() { var s = Sp(Rl()); return (Ct<T>(s[0]), Ct<T>(s[1]), Ct<T>(s[2]), Ct<T>(s[3])); }
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T, T, T, T, T) Tp5<T>() { var s = Sp(Rl()); return (Ct<T>(s[0]), Ct<T>(s[1]), Ct<T>(s[2]), Ct<T>(s[3]), Ct<T>(s[4])); }
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T, T, T, T, T, T) Tp6<T>() { var s = Sp(Rl()); return (Ct<T>(s[0]), Ct<T>(s[1]), Ct<T>(s[2]), Ct<T>(s[3]), Ct<T>(s[4]), Ct<T>(s[5])); }
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T1, T2) Tp2<T1, T2>() { var s = Sp(Rl()); return (Ct<T1>(s[0]), Ct<T2>(s[1])); }
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T1, T1, T2) Tp3<T1, T2>() { var s = Sp(Rl()); return (Ct<T1>(s[0]), Ct<T1>(s[1]), Ct<T2>(s[2])); }
}
public class Scr:Sc {
	private List<string> li = new List<string>();
	private int l = 0;
	private bool bo = false;
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	protected override string Rl() {
		if(bo) { return li[l++%li.Count]; }
		li.Add(Console.ReadLine());
		return li[li.Count-1];
	}
	public void Again() { bo=true; }
}
public class Sc2:Sc {
	private string[] sps = new string[] { " ","　","\t" };
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	protected override string[] Sp(string st) { return st.Split(sps,StringSplitOptions.RemoveEmptyEntries); }
	public override int I { get { return int.Parse(Sp(Rl())[0]); } }
	public override long L { get { return long.Parse(Sp(Rl())[0]); } }
	public override double D { get { return double.Parse(Sp(Rl())[0]); } }
	public override string S { get { return Sp(Rl())[0]; } }
}
public class Sct:Sc {
	private List<string> li = new List<string>();
	private int l = 0;
	public void Add(int s) { li.Add(s.ToString()); }
	public void Add(long s) { li.Add(s.ToString()); }
	public void Add(double s) { li.Add(s.ToString()); }
	public void Add(string s) { li.Add(s.ToString()); }
	public void Add(object s) { li.Add(s.ToString()); }
	public void Add(int[] s) { li.Add(string.Join(" ",s)); }
	public void Add(long[] s) { li.Add(string.Join(" ",s)); }
	public void Add(double[] s) { li.Add(string.Join(" ",s)); }
	public void Add(string[] s) { li.Add(string.Join(" ",s)); }
	public void Add(object[] s) { li.Add(string.Join(" ",s)); }
	protected override string Rl() { return li[l++]; }
	public void Clear() { li.Clear(); l=0; }
	public void Again() { l=0; }
	public void Pf() { Console.WriteLine(string.Join("\n",li)); }
}